1. Field of the Invention
This invention relates generally to building construction techniques, and more specifically to an improved method for constructing curvilinear structures.
2. Description of the Prior Art
Traditionally, buildings have been erected in generally rectangular configurations with the use of lumber, bricks, blocks and the like. These are rigid materials and may be most easily shaped with straight sides and square corners, which tends to require that structures built with such materials also have the same straight sides and square corners of rectangular configurations. Structures built from these materials have relatively low energy efficiency and require a high level of maintenance. They also tend to be fragile, and are more susceptible to storms, earthquakes, and fire than are other building shapes.
It is well known that curvilinear structures (such as domes) provide numerous benefits in structural integrity, longevity, and design flexibility. Structures with curved walls resist earthquakes, winds, snow loads, leaks, and the like, and are extremely energy efficient. However, the construction of curvilinear structures has been problematic.
Materials such as reinforced concrete can be molded into curved shapes, but forms are required to shape and support such materials in their initial fluid or plastic state. Since concrete forms have been generally constructed of lumber, it has been simpler and more economical to maintain the inherent rectilinear shape in the fabrication of forms and hence rectilinear concrete structures. Construction of wooden forms in complex curved shapes requires a great expenditure of materials, cost, time, and effort. In addition, building construction using concrete has necessitated the erection of two structures: first, wooden or foam forms are built, and secondly, the concrete is poured or sprayed and is temporarily held in place by the forms, then the wooden forms are removed and recycled or discarded.
Previous curvilinear structure construction utilized prefabricated elements or standardized parts limiting design flexibility and strength. Also, previous inventions required the use of off-standard utilities because the resultant structures had no flat walls. For example:
1. GEODESIC DOMES are usually made of wood; lack design flexibility; may constitute a fire hazard; use prefabricated panel kits, which create waste from endeavoring to construct triangular elements from rectangular materials; result in a conventional home built in a round space; and have off-standard utilities because there are no flat walls. PA0 2. AIRFORM-CAST CONCRETE STRUCTURES are ecologically dangerous in foam spraying; use Freon, a fluorocarbon that is damaging the ozone layer; lack design flexibility; have no flat walls; require specially trained workers to build; are a complex construction; and require specialized equipment and materials. PA0 3. STRUCTURAL FORM-CAST CONCRETE STRUCTURES such as those described in Pearcey et al. U.S. Pat. No. 4,352,260 provide a pre-fabricated system consisting of a steel skeleton which serves both as the forming system and as structural members in the finished dome shell, but these lack design flexibility and have aesthetic limitations are more costly than curvilinear structures and have limited openings.